A double-swirl spray nozzle which has two swirl chambers, one exit duct which widens in the direction towards an exit opening emanating from each of said swirl chambers, is disclosed in European Patent Document EP 1 491 260 B1. An angle of the wall of the exit duct in relation to a longitudinal central axis of the exit duct steadily increases in a few portions in the direction towards the exit opening while said angle remains identical in other portions. The double-swirl spray nozzle shown has both exit openings on the same side of the nozzle housing. The two exit openings are disposed at an angle in relation to one another. The double-swirl spray nozzle described is employed in flue gas purification plants, for example, in particular in gas scrubbers.
German Patent Document DE 100 33 781 C1 describes a double-swirl spray nozzle which has two swirl chambers and exit ducts which in each case emanate from the swirl chambers and run up to an exit opening. The exit openings are oriented towards opposite sides of the housing.